Chair base



This application is related to design patent application Ser. Nos. 29/305/602; 29/305,603; 29/305,605; 29/305,606; 29/305,607; 29/305,610; and 29/305,615, which are filed concurrently herewith.

FIG. 1 is a perspective view showing the front, left side, and top of a chair base which forms my new design, the broken lines of a chair and casters being for illustrative purposes only and forming no part of my design;

FIG. 2 is an enlarged perspective view thereof;

FIG. 3 is an enlarged top plan view thereof; and,

FIG. 4 is an enlarged front elevational view thereof. 

The ornamental design for a chair base, as shown and described. 